JP3338842B2 - Method and apparatus for altering compression of an internal combustion engine - Google Patents

Description

The present invention relates firstly to a method for changing the compression of an internal combustion engine of the type indicated in the preamble of claim 1, and secondly to a compression control device of the type indicated in the preamble of claim 7. .

State of the art Internal combustion engines of the type in question, for example row engines, have a cylinder receiving part which is pivotally connected to a crankcase part which supports the crankshaft of the engine by means of a tilt bearing device which connects the parts on one side of the engine. (Cylinder block). The cylinder receiving part supports a cylinder head forming the cylinder head of the engine. In the case of engines with overhead camshafts, they are mounted on the cylinder head. On the side of the engine opposite to the tilt bearing device, a tilting mechanism is arranged between the cylinder receiving part and the crankcase part, by which the cylinder receiving part and the cylinder head connected thereto are centered on the tilt bearing device. By pivoting, it can be tilted laterally relative to the crankcase part.

The distance between the crankshaft (connected to the piston) and the cylinder is variable, since the cylinder receiving part can be inclined laterally with respect to the crankcase part. In the upper turning position (top dead center) of the pistons, the volume of the part of the combustion chamber located above the upper limit plane of each piston can therefore be increased by the lateral inclination of the cylinder receiving part relative to the crankcase part. This means that the compression ratio of the engine is variable and that the efficiency of the engine can be optimized for changing drive loads, resulting in improved engine performance.

The tilt bearing arrangement between the crankcase part and the cylinder receiving part, as already mentioned, is arranged on one side of the engine, while the mechanism by which the cylinder receiving part can be tilted relative to the crankcase part is Located on the other side of the institution. The tilt bearing device is a laterally inclined shaft extending parallel to the crankshaft and fixedly connected to the crankcase part, preferably in a region below the laterally aligned ones along the outside of the cylinder receiving part. That is housed in a bearing bracket separated from the bracket. In the spacing between the bearing brackets, bearing lugs are arranged on a cylinder receiving part mounted on the part of the laterally inclined shaft located there. The tilt bearing device therefore comprises a bearing bracket, a lateral tilt shaft and a bearing lug, which together form a type of longitudinal hinge mechanism between the crankcase part and the cylinder receiving part.

The tilting mechanism on the opposite side of the engine may be, for example, an essentially vertically oriented rod similar to a connecting rod, the upper end of which is parallel to the crankshaft and which passes along the cylinder receiving part. Incorporates what can be rotated in. The lower end of the rod is eccentrically mounted on an eccentric shaft which is rotated in a bearing bracket fixedly connected to the crankcase part. The upper support shaft is in this case supported in the upper region of the cylinder receiving part by a bearing bracket fixedly connected to the cylinder receiving part. Thus, the distance between the upper support shaft and the bearing bracket that houses the eccentric shaft in the crankcase portion is changed by rotating the eccentric shaft. By changing this distance, this side of the cylinder receiving part can be raised or lowered relative to the crankcase part, which causes a lateral slope / tilt of the cylinder receiving part with respect to the crankcase part.

A bearing bracket connected to the crankcase part for a laterally inclined axis on one side of the engine and a bearing bracket also connected to the crankcase part for an eccentric axis on the other side of the engine are perpendicular to the crankcase. They are preferably arranged in pairs on the horizontal vertical plane between the cylinders.

One example of prior art in this field is USA2770224
It may be mentioned that the description describes a four-cylinder head-valve engine in which the cylinder receiving part is pivotally hinged to the fixed crankcase part together with the associated cylinder head / cover. The cylinder receiving part of the engine can in this case be inclined laterally on one longitudinal side of the engine about a longitudinal guide axis (laterally inclined axis) relative to the crankcase part. In the head-valve engine, the mechanism that causes the inclination of the cylinder receiving portion (side inclination) relative to the crankcase portion is a vacuum that causes the cylinder receiving portion to be inclined by the lever shaft mechanism with the crank journal attached. Incorporates a servomotor in the form of a tank. The vacuum used here is the vacuum generated by the negative pressure in the engine intake manifold. This means that a prohibitively large and bulky vacuum tank must be used and, in addition, it is not possible to obtain greater control than is possible due to the negative pressure generated in the intake manifold Therefore, the response of the servo motor is not appropriate.

According to this known design, a tilt control device which relies on external adjusting forces to produce the tilting movement must be used, and these adjusting forces are also totally dependent on the negative pressure obtained in the intake manifold. And is limited thereby.

OBJECTS OF THE INVENTION The main object of the present invention is to prevent the occurrence of the above-mentioned inherent disadvantages in known tilting mechanisms; It is to provide a method and apparatus that can be regulated without the need for pressure and without having to provide such forces and pressures to produce a side tilt.

The objectives mentioned above on the one hand include, on the one hand, that the method (of the type indicated in the preamble) takes the measures indicated in the characterizing part of claim 1, and, on the other hand, the method (indicated in the preamble). The present invention is achieved in that a compression control device (of the type described) exhibits the unique features set out in the characterizing part of claim 7.

Further advantageous developments of the method are given in dependent claims 2 to 6, and embodiments of the compression control device are given in claims 8 to 10.

The basic idea of the invention is that the energy of the kinetic gain obtained when the cylinder receiving part and the crankcase part are tilted and separated from each other (ie during the reduction of compression) is stored in the form of hydraulic pressure in the accumulator for later use Can be said to be.

The hydraulic energy thus stored can then be used to cause the cylinder receiving portion to tilt back toward the crankcase portion and return (i.e., to increase engine compression).

Stored and stored energy is generated inside the engine as a result of compression and combustion occurring within the engine cylinders. This stored energy is transferred from the cylinder receiving part in the form of movement of the tilting mechanism and the hydraulic piston and cylinder device coupled thereto.

BRIEF DESCRIPTION OF THE DRAWINGS The present invention will now be described and described in more detail with reference to the embodiments illustrated in the accompanying drawings.

FIGS. 1A, 1B, 2 and 3 show schematic end views of an internal combustion engine in which variable compression is caused by the lateral inclination of the cylinder receiving part relative to the crankcase part.

FIG. 4 shows the hydraulic piston and cylinder arrangement coupled to the tilting mechanism, together with the associated hydraulic circuit, only schematically, for an engine of the type shown in FIGS. 1A and 1B (max. FIG. 3 shows a longitudinal section (in a position for compression).

FIG. 5 shows the engine according to FIG. 4 in a position in which the cylinder receiving part is at a maximum lateral inclination for minimum compression.

FIG. 6 schematically shows, in perspective view, the essential parts of a tilting mechanism for raising / lowering the right side of the cylinder receiving part of the engine in a design of the type shown in FIGS.

DESCRIPTION OF THE EMBODIMENTS The invention can be used, for example, to drive a passenger car. An Otto-type four-cylinder in-line engine will be described below.

Engines with overhead camshafts are designed so that their compression ratio can be changed. This is achieved by the fact that the cylinder receiving part 2 of the engine is mounted on the engine crankcase part 4 on which the crankcase 6 is mounted so that it can be tilted sideways. The lateral inclination of the cylinder receiving part 2 occurs on one side (left side in the illustrated design) of the engine, about the inclination bearing 8.

1A and 1B show an alternative position of the tilt bearing 8 between the cylinder receiving part and the crankcase part. 1A and 1B show a tilt bearing located at the lower edge of the cylinder receiving portion, while FIG. 2 shows a tilt bearing located at the upper edge of the cylinder receiving portion, and FIGS. FIG. 3 shows a tilt bearing arranged on the side of the same height as the crankshaft below the crankcase part. 1A
For the design types according to FIGS., 1B, 2 and 3, the cylinder receiving part 2 is generally integrated with the associated cylinder head 29 or detachably bolted or screwed. In reality, it is detachably connected to a cylinder head by a joint.

FIGS. 4 to 6 show an embodiment in which the tilt bearing 8 is arranged as shown in FIGS. 1A and 1B.
Reference is mainly made to the figures.

The row engine has a cylinder receiving part 2 (with four cylinders 10, see FIG. 4) and a crankcase part 4 on which a crankshaft 6 is mounted. In FIG. 4, the crank journal of the crankshaft 6 is indicated by 12. A piston 14 that moves in each cylinder 10
And the piston is connected by a connecting rod 16 to the associated crank journal portion 12 of the crankshaft 6. There is also a sump at the bottom of the crankcase 4, which is not shown in the drawing.

On the left side of FIG. 4, the cylinder receiving part 2 has, at the bottom, four bearing lugs 18 (only one is shown in FIGS. 4 and 5), on which the inclined or laterally inclined axis is located. The shaft is mounted on five bearing brackets connected to the crankcase part 4, the middle three of which are located between bearing lugs 18,
And the outermost two receive the ends of the shaft 20. The tilt bearing 8 allows the cylinder receiving part 2 to tilt about the shaft 20 relative to the crankcase part 4.
The crankshaft 6 is mounted in the crankcase part 4 and the piston 14 is connected to the crankshaft, so that while the part 2 is pivoted away from the crankshaft by side tilt, the cylinder 10 It can be displaced obliquely upward and outward a short distance relative to 14. This relative movement between each piston and the associated cylinder causes a certain drop or retraction of the piston within the cylinder, which creates an excess volume 22 (in the combustion chamber on piston 14 when the piston is in the top dead center position). (See FIG. 5). This results in an appropriately reduced compression ratio for the engine components 2, 4 in the position shown in FIG.

The crankcase part 4 has raised transverse walls 24, 26 extending approximately to the level of the upper surface 28 of the part 2. Also at the front and rear ends of the engine are gearboxes and end plates (not shown) which form the front and rear end walls of the crankcase part 4, respectively, and which are connected to the transverse walls 24, 26 respectively.
Also, the gearbox and endplate terminate at essentially the same height as the height at which surface 28 was located. The cylinder receiving part 2 is therefore surrounded on all sides by walls. The transverse walls 24, 26 need not necessarily be integral with the crankcase part 4, but may instead constitute a separate wall part attached to the crankcase part 4.

Inlet and outlet ducts 30, 32, inlet and outlet valves 34,
36, and cylinder head 29 with overhead camshafts 38, 40
Are fixed to the surface 28 of the cylinder receiving part 2. Also,
Conventional mechanisms (not shown), such as suction and discharge systems and devices for fuel injection, supercharging and exhaust purification, are coupled to the inlet and outlet ducts.

Between the cylinder head 29 and the cylinder receiving part 2 is a cylinder head gasket 42, and between the part 2 and the side walls 24, 26 and the gearbox and end plates extends along the entire periphery of the part 2. An elastic seal 44 is provided to help seal the engine crankcase. The seal is movable, can be bent up and down, and is designed to guarantee different vertical positions in different areas. The inner edge 46 of the seal is tightly clamped between the cylinder head 29 and the cylinder receiving part 2. A plate edge is cast into the outer edge of the seal 44 and is secured by a joint 48 so as to seal against the upper surfaces of the walls 24, 26, the gearbox and the end plate.

A tilt mechanism 70 is arranged on the side of the engine opposite to the tilt axis 20, which works between the crankcase part 4 and the cylinder receiving part 2, and provides for the distance between the engine parts 2 and 4. It helps to make a change and change the compression. The tilting mechanism 70 has four rods 50 similar to connecting rods
(See FIG. 6), and the upper end of the rod is the cylinder receiving portion 2
Are pivotally mounted on a longitudinal shaft 52 housed in five bearing brackets 54 coupled to the shaft. At its lower end, a bar 50 is pivotally mounted on an eccentric shaft 56, which is rotatably mounted on five bearing brackets 58 secured to the crankcase portion. At the lower end, the bar 50 has a bearing cap 60 for easy assembly / removal of the lower end to the shaft 56.

As shown in FIG. 4, the tilting mechanism 70 includes a lateral direction coupled to a hydraulic control 76 to control the lateral tilt of the cylinder receiving portion 2 relative to the crankcase portion 4 caused by rotation about the tilt bearing 8. Are connected by a lever 74 projecting from

The lever 74 is eccentrically arranged and the shaft 56 is
Can be fixedly attached to, or fixedly coupled to, one of the enlarged bearing portions 72 (see FIG. 6) thereby attached. The lever 74 can also be fixed to a bearing part 72 ′ that projects axially from a bearing bracket 58 arranged at the end of the crankcase part 4, for example.

As shown, the hydraulic control device 76 is a piston and cylinder device 78 comprising a cylinder housing 80 with a piston 82 articulated to a lever 74 and moving rearward and forward within the lever 74. A protruding piston rod 84 has a hinge 88 at its outer end.
One that is fixed to the frame part 86 via the is incorporated. Frame portion 86 may form part of crankcase portion 4 or may be fixedly coupled to crankcase portion by other means. Cylinder housing
80 is a lever 74 through a hinge 90 with an axial extension 89
Is pivotally connected to the The piston 82 divides the inside of the cylinder housing 80 into a first chamber 92 and a second chamber 94.

Chamber 92 is fluidly connected to the accumulator 96 via a pipe 98 incorporating a check valve device 100, the inverse valve device two alternative flow paths with opposite flow direction, i.e. S ₁ direction are lower branch flow passage, the provided for flow onto the branch flow path and S ₂ direction for flow to. Upstream path has a shut-off valve C which can be controlled by the check valve 102 and an electromagnet which is open S ₁ direction, whereas, the downstream path may be controlled by the check valve 104 and an electromagnet which is open S ₂ direction blocking Valve B
Having. When reducing engine compression, the chamber 92 is charged with an accumulator 96
Between the cylinder receiving portion 2 and the crankcase portion 4, the separation force generated by the compression and combustion in the cylinder 10 causes the rotation of the shaft 56 and the bearing portion 72 and the displacement of the piston 82 in the cylinder housing 80. The fluid pressure stored in the accumulator 96 may be generated via the displacement.

Chamber 94 is connected to a hydraulic fluid reservoir 108 by a hydraulic tube 106. The flow pipe 106 is regulated by a shut-off valve A controlled by an electromagnet. Tube 106 is throttle 110
Is incorporated.

The accumulator 96 is shown in FIG. 4 and is provided with an adjustable preload spring 132 which balances the pressure, the active elasticity of the spring being such that the upper end of the spring is in contact with the holding plate 134 A regulator 136, supported and whose axial position in the accumulator 96 can even displace the plate 134 by its push rod 138 mounted on the plate 134, thereby changing the force of the spring 132 It can be adjusted because it can be adjusted.

Spring 132 is designed to be sufficiently adjustable to balance forces in the hydraulic system. Thus, only a small additional force is required for the adjustment.
In other words, elasticity in the hydraulic system (ie, the force from spring 132 in accumulator 96) can be used to balance the forces. Thus, a relatively weak regulator can perform the work required for engine regulation.

Instead of a design using the adjustment spring 132 in the accumulator 96, an alternative design could be envisioned with a small hydraulic pump that could be used to pressurize the hydraulic adjustment system in selected areas.

Before turning to an explanation of how the hydraulic regulator 76 coupled to the tilt mechanism 70 works, the applicant will briefly remind the reader of the objects and means of the present invention.

The work of the method and the compression regulating device to which the present invention relates are:
The purpose is to provide a controlled side tilt of the cylinder receiving part 2 relative to the crankcase part 4 of the engine. The concept behind this is to use the internal separating force between the cylinder receiving part and the crankcase part generated in the engine by compression and combustion in the cylinder, and later the cylinder receiving part The separation force is stored in a pressure accumulator for use when contracting in the direction of the crankcase portion to increase. For engine loads where rapid adjustment of compression is desired,
That is, when required to reduce compression primarily, the separating force causes the cylinder receiving portion to become totally or partially sloping away from the crankcase portion, with a corresponding reduction in compression.

Engine compression is regulated by regulator 76 as follows: When regulating to produce reduced compression, valve B is first opened and thus internal engine forces (ie, engine cylinders resulting from compression and combustion). Compression force) allows the cylinder receiving part 2 to be tilted away from the crankcase part 4. In this case, the lever 74 is pivoted upward (counterclockwise, as shown in FIG. 4), causing the cylinder housing 80 to be pulled upward, so that the piston 82 compresses the hydraulic fluid in the chamber 92. Then room
The increasing pressure of the hydraulic fluid in 92 is transmitted via line 98, check valve 104 and valve B to an accumulator 96, which is thus charged and the future adjustment and resetting of lever 74 in the opposite direction. It forms a potential source of force that can be used later for positioning.

When regulating to produce increased compression, valve C is initially opened (valve B is therefore closed), and thus the hydraulic pressure previously stored in accumulator 96 is applied to line 98, valve C and check valve 102.
To the chamber 92, whereby the piston-cylinder arrangement 78 is compressed and the lever 74 is pivoted downward (clockwise in FIG. 4). This is the bearing bracket 58
Has the effect of rotating the bearing parts 72, 72 ', so that the eccentrically arranged shaft 56 moves downward along the arc (towards the limit position shown in FIG. 4) and the cylinder receiving part 2 is cranked. The case part 4 is inclined downward. When valves B and C are opened, valve A is also opened to prevent pressure from being created in chamber 94 which would prevent regulation.

The adjustment of valves A, B and C is controlled by control unit 112, which adjusts the engine compression ratio so that it is optimal with respect to engine operating conditions. At least load and speed transmitters are used to sense operating conditions of the engine, and for example, angular position transmitters located on either shaft 20, 56 or transmitters located in cylinder housing 80 are compressed. Used for feedback.

FIG. 4 schematically shows how the control unit 112 receives input signals from the load transmitter 114, the speed transmitter 116 and the angular position transmitter 118. The signals are transmitted to the control unit via signal cables 120, 122 and 124, respectively.

The valves A, B and C are controlled by their associated electromagnets, their activation (for opening / closing the valve) is controlled by the control unit 112, for which purpose the control unit is provided with a control output device Output signals are then transmitted to the electromagnet through signal cables 126, 128 and 130, respectively.

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int. Cl. ⁷ , DB name) F02B 75/04 F02D 15/04

Claims (10)

(57) [Claims] An internal combustion engine wherein a cylinder receiving portion (2) of the engine is pivotally mounted about a tilt bearing (8) in a crankcase portion (4) of the engine supporting a crankshaft. A tilting mechanism which works between the crankcase part and the cylinder receiving part and allows the distance between the crankcase part and the cylinder receiving part (2, 4) to be adjusted on the side of the engine opposite the tilt bearing (70)
In a method for varying the compression of an internal combustion engine, the inclination of which is achieved by an adjusting mechanism having a hydraulic piston and cylinder device (78) coupled between a crankcase part (4) and a cylinder receiving part (2). Tilting mechanism (70) for changing the distance between the crankcase part and the cylinder receiving part (4, 2) adjusted by the effective length of (78)
The piston (82) of the piston-cylinder device (78) moving in the cylinder housing (80)
4) and one of the chambers (94) can be fluidly connected to the reservoir (108) to refill or empty the chamber (94), and the other one (92) of the chambers Accumulator (9
6) can be fluidly connected to the method. 2. The method according to claim 1, wherein the adjusting mechanism is mounted so as to rotate relative to the crankcase part, the torsion position of the adjusting mechanism being variable. A mechanism that is adjusted to correspond to a change in the distance between the cylinder receiving portion and the crankcase portion (56,
72), wherein the torsional movement of the mechanism (56, 72) is used to change the effective length of the piston and cylinder device (78). 3. The method according to claim 2, wherein the torsional movement of the rotatably mounted mechanism is fixedly mounted on the mechanism and the cylinder housing of the device. Transmitted to a movement that changes the linear length of the piston-cylinder arrangement (78) by means of a lever (74) that is hinged to the lever. 4. The method as claimed in claim 3, wherein the piston (8) moves in a cylinder housing (800) of the device.
2) The method characterized in that 2) is pivotally fixed to a fixed support point (86) with respect to the crankcase (4) by the end of its piston rod (84) projecting from the cylinder housing. 5. The method according to claim 2, wherein the adjustment for reducing the compression of the engine is achieved by connecting the chamber (92) to the accumulator (96), while the cylinder receiving part and the crankcase part. The separation force generated by the compression and combustion in the engine cylinder generates fluid pressure as a result of rotation of the mechanism (56, 72) and displacement of the piston (82) in the cylinder housing (80) of the device. The pressure is stored in an accumulator (96). 6. The method as claimed in claim 2, wherein the adjustment for increasing the compression of the engine comprises a cylinder receiving part (2) providing rotation of the mechanism (56, 72) and a crankcase part (12). 4) transferring fluid pressure from the accumulator (96) to one of the chambers (92) of the piston-cylinder device (78) in order to achieve a reduction in the effective length of said device so as to achieve the contraction of 4). A method characterized by being performed by: 7. In order to achieve variable compression of the engine, it is pivotally mounted in the crankcase part (4) of the engine supporting the crankshaft, centered on a tilt bearing (8) on one side of the engine. Cylinder receiving part (2), while
A tilting mechanism (70) which works between the crankcase part and the cylinder receiving part and serves to achieve a change in the distance between these two engine parts, and thus a change in the engine compression ratio, is opposed to a tilt bearing (8). A compression adjusting device for an internal combustion engine arranged on the side of the engine, wherein the hydraulic adjusting device (76, 78)
Are connected to a tilting mechanism (70) for adjusting the lateral tilt of the cylinder receiving part (2) with respect to the crankcase part (4) occurring around the tilt bearing, the adjusting device being mainly supplied with external driving force. Without operating and simply using hydraulic energy stored in a pressure accumulator (96) belonging to the regulating device, said pressure accumulator being obtained from compression and combustion in the engine cylinder and A compression regulating device, characterized in that it is designed to be filled with pressure energy transmitted to the accumulator (96) via the tilting mechanism (70) and the regulating devices (76, 78). 8. The compression adjusting device according to claim 7, wherein:
Engine cylinder receiving part (2) is overhead camshaft (38, 40)
A bearing lug (54) for supporting the cylinder head (29) mounted therein and constituting an upper fastener for the tilting mechanism (70), the tilting mechanism comprising a bearing lug (54). Having a connecting element (50) resembling a connecting rod between an upper support shaft (52) installed therein and a lower eccentric shaft (56) rotatably mounted in the crankcase part (4). In the compression adjusting device, the hydraulic adjusting device (76, 78) has at least one lever (74) fixedly connected to the eccentric shaft (56) and secondly its cylinder housing (8).
0) is hinged to the free outer end of the lever (90) and its piston rod (84) protruding from the cylinder housing connects its free outer end to the crankcase part (4,8).
6) and a hydraulic piston / cylinder device (78) connected by a hinge (88) to the first chamber (92) in the cylinder housing (80) arranged on the piston rod side of the piston (82). ) The pressure accumulator (96) by the check valve device (100)
Wherein the second chamber (94) opposite the piston is connected to a hydraulic fluid reservoir (108). 9. The compression adjusting device according to claim 8, wherein
Non-return valve (104, 102) with non-return valve devices (100) connected in parallel together and open in opposite directions
A compression regulating device having a pair of electrically controlled shut-off valves (B, C) connected to the first chamber (92) by the first and second valves. 10. The compression regulating device according to claim 8, wherein the second chamber (94) is simultaneously opened with one of the shut-off valves (B, C) incorporated in the check valve device (100). A compression regulator, characterized in that it is connected to a hydraulic fluid reservoir (108) by an electrically controlled shut-off valve (A) designed to be opened.